Functional dependence is a common and morbid problem for community-living older persons, with prevalence rates exceeding 10 percent for dependence in basic (i.e. self-care) activities of daily living (ADLs) and 15-20 percent for dependence in instrumental activities of daily living (IADLs) and mobility. The overall aim of this revised application, which is being led by a New Investigator, is to further elucidate the mechanisms underlying the development of, and recovery from, functional dependence among community-living older persons. Our primary aim is to determine the effects of baseline vulnerability and intervening events on the risk of functional dependence. Baseline vulnerability is defined on the basis of three factors (physical capability, cognitive status, and age) that we have found to be most strongly associated with the development of functional dependence. Intervening events include acute hospital admissions and nonhospital events, defined as episodes of illness, injury or other problems associated with restricted activity. Our two secondary aims are to identify the specific nonhospital events that are associated with the onset of functional dependence, and to identify the factors that either facilitate or impede recovery from functional dependence. We will use data from an ongoing longitudinal study of 753 community-living persons, 70+ years, who upon enrollment were independent in their basic ADLs. Baseline vulnerability and functional status were determined during a comprehensive home- based assessment which will be repeated at 18 months. Participants are subsequently followed with monthly telephone interviews for three years to ascertain their exposure to intervening events and to reassess their functional status. Our primary outcome is the onset of persistent ADL dependence, defined as a new disability (requiring personal assistance) in one or more basic ADLs that is present for at least two consecutive months. Important secondary outcomes include new dependence in IADL function and mobility. The unique strengths of this research include the availability of high quality data from a well-defined cohort of community-living older persons; nearly complete ascertainment of intervening events and updated information on functional status gathered from monthly telephone interviews; and the research team's vast experience in longitudinal studies of functioning in older persons. The results of this research will provide important insights into the mechanisms underlying the disablement process and will facilitate the development of effective and efficient strategies to prevent the onset and progression of functional dependence among at-risk elders.